Các câu hỏi tương tự
Chứng tỏ :\(\frac{23}{34}<\frac{1}{31}+\frac{1}{32}+...+\frac{1}{70}<\frac{4}{3}\)
Chứng tỏ :\(\frac{23}{34}<\frac{1}{31}+\frac{1}{32}+\frac{1}{33}+...+\frac{1}{70}<\frac{4}{3}\)
Chứng tỏ rằng :\(\frac{23}{34}<\frac{1}{31}+\frac{1}{32}+...+\frac{1}{70}<\frac{4}{3}\)
Chứng minh rằng :\(\frac{23}{34}<\frac{1}{31}+\frac{1}{32}+\frac{1}{33}+...+\frac{1}{70}<\frac{4}{3}\)
Chưng minh rằng:\(\frac{23}{34}<\frac{1}{31}+\frac{1}{32}+\frac{1}{33}+...+\frac{1}{70}<\frac{4}{3}\)
Chứng tỏ:
\(\frac{31}{2}.\frac{32}{2}.\frac{33}{2}.\frac{34}{2}....\frac{60}{2}=1.3.5....59\)
Cho \(S=\frac{1}{31}+\frac{1}{32}+\frac{1}{33}+\frac{1}{34}+...+\frac{1}{60}\)
CMR : \(\frac{3}{5}< S< \frac{4}{5}\)
Cho B = \(\frac{1}{31}\)+\(\frac{1}{32}\)+\(\frac{1}{33}\)+.....+\(\frac{1}{60}\)
Chứng tỏ rằng \(\frac{3}{5}\)< B<\(\frac{4}{5}\)
A) Chứng tỏ:\(\frac{1}{3}+\frac{1}{31}+\frac{1}{35}+\frac{1}{37}+\frac{1}{47}+\frac{1}{53}+\frac{1}{61}< \frac{1}{2}\)
B)Tìm cặp số nguyên (x,y) sao cho:
\(\left(x-5\right).\left(x-y+1\right)=-23\)